feat: add official EmDash marketing template

- Marketing landing page with hero, features, testimonials, FAQ, pricing
- EmDash CMS with pages collection and marketing blocks
- Full seed data with all content sections
- Dockerfile with entrypoint for database persistence
- Responsive design with CSS variables

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/blocks/Testimonials.astro

@@ -0,0 +1,29 @@
+---
+interface Props {
+	node: {
+		_key?: string;
+		headline?: string;
+		testimonials: Array<{
+			quote: string;
+			author: string;
+			role?: string;
+			company?: string;
+		}>;
+	};
+}
+
+const { node } = Astro.props;
+const { headline, testimonials } = node;
+---
+
+{headline && <h2>{headline}</h2>}
+
+{testimonials?.map((t) => (
+	<blockquote>
+		<p>"{t.quote}"</p>
+		<footer>
+			<cite>{t.author}</cite>
+			{t.role && <span>{t.role}{t.company && ` at ${t.company}`}</span>}
+		</footer>
+	</blockquote>
+))}